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| author |   Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2020-11-22 09:33:09 -0800 |
|---|---|---|
| committer |   Michał Górny <mgorny@gentoo.org> | 2020-12-14 11:00:29 +0100 |
| commit | df5f5b6f5be561d62e5a5771f0dc5ac34302bb0b (patch) | |
| tree | bf7fbb32053fd0da6380eea9038ea1ae499ce304 /.azure-pipelines | |
| parent | [3.7] bpo-42103: Improve validation of Plist files. (GH-22882) (#23117) (diff) | |
| download | cpython-gentoo-3.7.9-r1.tar.gz cpython-gentoo-3.7.9-r1.tar.bz2 cpython-gentoo-3.7.9-r1.zip | |
bpo-40791: Make compare_digest more constant-time. (GH-23438)gentoo-3.7.9-r1
The existing volatile `left`/`right` pointers guarantee that the reads will all occur, but does not guarantee that they will be _used_. So a compiler can still short-circuit the loop, saving e.g. the overhead of doing the xors and especially the overhead of the data dependency between `result` and the reads. That would change performance depending on where the first unequal byte occurs. This change removes that optimization.
(This is change GH-1 from https://bugs.python.org/issue40791 .)
(cherry picked from commit 31729366e2bc09632e78f3896dbce0ae64914f28)
Co-authored-by: Devin Jeanpierre <jeanpierreda@google.com>
Diffstat (limited to '.azure-pipelines')
0 files changed, 0 insertions, 0 deletions